The Mechanical Handling and Storing of Material

COALING VESSELS AE SEA 325 of the warship. This endless rope was to have buckets of coal secured to it at frequent intervals, and the whole was to be operated by a capstan, the coal being thus passed from one ship to another. This plan was of course subjected to the same criticisms as that of Lieutenant Bell, namely, that in any seaway whatsoever the cable would either be dropped into the sea by excessive slack or snapped by pitching in the reverse direction. Low’s Plan.—The Hon. Phillip B. Low secured a patent, 10th July 1893, on a plan practically the same as that Lieutenant Bell described in his paper six years earlier, but with the important addition of a counterweight secured to the end of an elevated carrying cable (Fig. 466). This counterweight was so arranged as to maintain a constant tension on the suspended cable, regardless of the motion of the ships. The use of a counterweight to maintain a constant tension on a suspended wire rope would be successful in any stationary plant on shore. His plan was tested by the United States Navy Department in October 1893. The test took place on board the U.S.S. “San Francisco” and the U.S.S. “ Kearsarge.” The distance from the shears of the cruisers to the upright poles on the colliers was about 235 ft., hence the distance between the vessels was somewhat less than 200 ft. The transmission wire, as the inventor called it, was secured to the deck of the “San Francisco,” supported by a pair of shear-poles at the stern, then run on Fig. 465. Diagram showing Lieutenant Tupper’s Plan for Coaling at Sea. Fig. 466. Low’s Plan for Coaling at Sea. * an incline to a gin-pole at an elevation of about 32 ft. above the foremast of the “ Kearsarge,” which played the part of the collier, and so gave a gradient of about 8° to the horizontal between the rope terminals and the vessels. After the cable was threaded through the gin-block it was bent backwards, while to the end was secured a counter- weight of about 1,600 lb. The bags of coal weighed nearly 200 lb., and the time required to travel from the pole-head on the collier was about fourteen seconds. To hoist and send over ten bags of coal occupied some twenty minutes, giving about the rate of 2| tons per hour. The Board of Naval Officers were instructed to report on the trial, and their official report was that in rough weather the apparatus would not be of the slightest use in transferring coal from one vessel to another. The apparatus was reported to have worked well; but as the sea was calm, it was impossible to say what would have been the result in a moderate sea. As the sea became heavier, the distance between the ships would have to be increased for safety, and there would have to be a corresponding increase in the height of the gin-block in order to give a proper inclination to the connecting rope. Presuming that the distance between ships was increased 300 ft., the same angle of inclination preserved, and the same height of shear-poles on the warship, then the gin-block on the collier would have to be 70 ft. above the deck of that craft, as this would reach to the truck of the foremast of the collier. It is clear that to attempt to attach bags of coal at such a height would be difficult, if not altogether impracticable, especially in a rolling sea. Even then the capacity, whatever it might have been at